This invention relates in general to electrography and, in particular, to hybrid compounds, thin films and processes for preparing and using the hybrid compounds and thin films in, for example, preparing dielectric electroreceptor devices for use with liquid ink development systems. In fabricating electrographic imaging members, there is a need for materials which can be easily prepared and which have a high level of mechanical stability and solvent resistance. There are known a number of methods and materials for forming electrographic imaging members, for example, the aforementioned copending application U.S. application Ser. No. 07/815,215 filed Dec. 31, 1991. Illustrated in the copending applications are devices having blocking layers which layers are required for the devices to be effective.
In electrography, an electrostatic latent image is formed on a dielectric imaging layer (electroreceptor) by various techniques such as by an ion stream (ionography), stylus, shaped electrode, and the like. Development of the electrostatic latent image may be effected by the application of certain electrostatically charged marking particles in either dry form or dispersed in liquid media.
A hybrid composition or volume grafted elastomer comprising a fluoroelastomer and a polyorganosiloxane that forms an integral interpenetrating network has been disclosed in the aforementioned commonly assigned U.S. Pat. No. 5,166,031. The volume graft composition was used in fabricating a thermal fusing member for use, for example, in fusing electrographic toner images.
Fluoroelastomers, such as VITON.RTM., may be coated directly onto metallic substrates such as aluminum, steel or other suitable ground planes to form dielectric receivers. When these fluoroelastomer coated ground plane devices are corona charged by known means, the devices exhibit high charge injection rates which results in noncapacitive charging thereby causing high charge decay rates and low development potentials. These results render fluoroelastomer coated devices undesirable from a charging perspective. However, fluoroelastomers possess desirable mechanical properties, for example, durability, flexibility, solvent resistance, and the like, which make them particularly attractive for use in electroreceptor devices. The aforementioned high charge injection rates can be controlled and lowered by applying a blocking layer at an interface formed between the ground plane and the fluoroelastomer. However, the application of the blocking layer requires an additional coating step and additional drying and curing time which may reduce yields and unnecessarily inflates manufacturing costs.
There continues to be a need for improved fluoroelastomers or hybrid compositions which embody both desired mechanical properties and low charge injection rate properties and which fluoroelastomers or hybrid compositions may be directly applied to a ground plane metallic substrate in a single step without requiring the application of an intermediate blocking layer at the interface between the ground plane and the dielectric fluoroelastomer layer in a separate step. There is a continuing need for electroreceptor devices that are: convenient to prepare, economic, environmentally acceptable, mechanically stable and highly durable, having low charge injection and high capacitive charging properties.